ffmpeg/libavcodec/alpha/mpegvideo_alpha.c

89 lines
2.4 KiB
C

/*
* Alpha optimized DSP utils
* Copyright (c) 2002 Falk Hueffner <falk@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "asm.h"
#include "../dsputil.h"
#include "../mpegvideo.h"
extern UINT8 zigzag_end[64];
static void dct_unquantize_h263_axp(MpegEncContext *s,
DCTELEM *block, int n, int qscale)
{
int i, level;
UINT64 qmul, qadd;
if (s->mb_intra) {
if (n < 4)
block[0] = block[0] * s->y_dc_scale;
else
block[0] = block[0] * s->c_dc_scale;
/* Catch up to aligned point. */
qmul = s->qscale << 1;
qadd = (s->qscale - 1) | 1;
for (i = 1; i < 4; ++i) {
level = block[i];
if (level) {
if (level < 0) {
level = level * qmul - qadd;
} else {
level = level * qmul + qadd;
}
block[i] = level;
}
}
block += 4;
i = 60 / 4;
} else {
i = zigzag_end[s->block_last_index[n]] / 4;
}
qmul = s->qscale << 1;
qadd = WORD_VEC((qscale - 1) | 1);
do {
UINT64 levels, negmask, zeromask, corr;
levels = ldq(block);
if (levels == 0)
continue;
zeromask = cmpbge(0, levels);
zeromask &= zeromask >> 1;
/* Negate all negative words. */
negmask = maxsw4(levels, WORD_VEC(0xffff)); /* negative -> ffff (-1) */
negmask = minsw4(negmask, 0); /* positive -> 0000 (0) */
corr = negmask & WORD_VEC(0x0001); /* twos-complement correction */
levels ^= negmask;
levels += corr;
levels = levels * qmul;
levels += zap(qadd, zeromask);
/* Re-negate negative words. */
levels -= corr;
levels ^= negmask;
stq(levels, block);
} while (block += 4, --i);
}
void MPV_common_init_axp(MpegEncContext *s)
{
if (amask(AMASK_MVI) == 0) {
if (s->out_format == FMT_H263)
s->dct_unquantize = dct_unquantize_h263_axp;
}
}